Ulster

Ulster is a province of Ireland, and the home of the "good guys" of the story, the Ulstermen and their hero, Cuchulainn. They are afflicted by a curse that causes them to become immobilized with labor-type pains occasionally.

Connacht

Connacht is the province of Ireland where Ailill and Medb hail from. It is chiefly Connachtmen who compose the army that battles Ulster.

Donn Cuailnge

Donn Cuailnge is the name of the prize bull which Medb seeks and wages war for, the cause for the Tain of the title.

Gae Bolga

The gae bolga is a many-barbed spear, a sort of secret weapon that Scathach taught Cuchulainn and seemingly no one else. The two times Cuchulainn is evenly matched and in trouble (versus his own son, and versus Ferdia), he employs the gae bolga to dispatch his foe, which spreads barbs throughout a person's body.